5/19/2006

So far in the current series of posts, I have covered how Schacter's "seven sins of memory" can be more parsimoniously explained as arising from three types of system failure. The first, failures of maintenance, roughly map on to his sin of transience. The second, failures of search, explain both suppression related phenomena as well as interference and transfer appropriate processing. But what about the third type of system failure, what I have termed "monitoring failure"?

A particular memory inaccuracy is likely to involve monitoring failure if a memory search has returned results, but these are taken to be valid results of the search cues when in fact they should not. Schacter categorizes this type of failure in three different ways: suggestibility, misattribution, and bias. It is not clear that these are fundamentally different. In fact, as discussed below, all of the evidence Schacter used to exemplify these “sins” can be more parsimoniously interpreted as failure to correctly evaluate the validity of results from a memory search.

For example, source misattribution errors occur when people insist that they saw someone in one context when in fact they saw them in another, or may incorrectly attribute some piece of trivia as coming from a newspaper, when in fact it was provided by the experimenter. These results can clearly be taken as instances of faulty monitoring of memory search results. Similarly, false recall or recognition in the Deese-Roediger-McDermott paradigm can be seen as a kind of monitoring failure, in which the feelings of familiarity are falsely monitored as indicating that the target word was present, when in fact it was not. The “false fame” effect is yet another example, where previously studied names are considered more likely to be famous than new names.

Although Schacter classifies these misattribution inaccuracies as distinct from suggestibility, this distinction may not be necessary. In a strict sense, errors resulting from suggestibility (for example, the subtle influences of question phrasing on the retelling of traffic accidents) can be viewed as misattribution errors, where the emphasis that originates from the question is instead falsely monitored as originating from the content of the memory itself.Schacter also categorizes memory biases as distinct from both of these, although they too can be considered instances of monitoring failure, as explained below.

For example, humans show a consistency bias when asked how similar their previous attitudes are to their current attitudes, and tend to overestimate the similarity between current and previous attitudes. This might easily result from a memory search returning current as well as past attitudes towards an issue, despite the proper cues being provided to memory. In this case, faulty monitoring of memory search results might allow some current attitudes to “taint” the perception of previous attitudes, and result in the perception of increased similarity.

On the other hand, when people have reason to believe that their skills or opinions have changed substantially, retrospective biases tend to move in the opposite direction, such that people tend to overestimate the amount they may have changed. Interestingly, faulty monitoring may also be the culprit in this case: despite accurately probing memory, the memory search may also return related current attitudes (presumably those that strongly represent the idea that change has occurred). These results may influence the magnitude of perceived difference between current and previous time points, such that failure to exclude the current attitude (with a strong representation of “change”) may exaggerate the differences between current and previous attitudes.

The aforementioned grouping of bias, suggestibility, and misattribution under the umbrella of “monitoring failure” has additional advantages. For example, “faulty monitoring” might also be at work in other phenomena, such as confabulation. This refers to the phenomenon where some patients with frontal damage will unintentionally fabricate stories about their past. This is not a failure of memory search, because it is clear that the patients know the kind of information they should be looking for – autobiographical facts. However, the results of this search are mistakenly regarded as accurate, as opposed to being correctly monitored (and discarded) as inaccurate.

In the next (and final) post in this series, I will give additional evidence on how these categories of memory failure are superior to the "seven sins" (despite not being as catchy!). Furthermore, this framework makes some interesting predictions about how more complicated memory failures - such as déjà vu - may arise as an interaction between multiple systems.

Note: This post is part 5 (part 1, part 2, part 3, part 4) in a series, in which I'll review and revise Schacter's "seven sins of memory" according to a new framework of memory failure, one that is both closer to neuroanatomy and wider in scope.

6 Comments:

From the initial resurrection (and renaming) of the Deese-Roediger-McDermott paradigm, I've had a hard time believing the phenomenon was an instance of "false memory" rather than just semantic priming. Yes, you're failing to reject the close semantic associate "sleep" after studying bed, tired, pillow, dream etc., but this is nothing like the "false memory" furor in the headlines at the time (the mid-90's or so). There was a great, fairly recent article that critiqued the terminology used to explain DRM false alarms... but I don't recall the author!

Anyway, even Schacter et al. have backed away a bit from calling it "false memory." Alzheimer's patients, who have decrements in both episodic and semantic memory, are less susceptible to the DRM effect. They're now talking about gist memory, e.g.,

What's in a Name for Memory Errors? Implications and Ethical Issues Arising From the Use of the Term "False Memory" for Errors in Memory for Details

Anne P. DePrince, Carolyn B. Allard, Hannah Oh, Jennifer J. Freyd

The term "false memories" has been used to refer to suggestibility experiments in which whole events are apparently confabulated and in media accounts of contested memories of childhood abuse. Since 1992 psychologists have increasingly used the term "false memory" when discussing memory errors for details, such as specific words within word lists. Use of the term to refer to errors in details is a shift in language away from other terms used historically (e.g., "memory intrusions"). We empirically examine this shift in language and discuss implications of the new use of the term "false memories." Use of the term presents serious ethical challenges to the data-interpretation process by encouraging over-generalization and misapplication of research findings on word memory to social issues.

I have really enjoyed this series of yours. A visit to your site is rarely disappointing. (Yours too, NCrit.)

This post in particular is of interest to me; I've been reading Schacter's stuff as of late, for an odd reason:a couple of weeks back, I had an odd thing happen. I was driving along a winding country road at about 60 mph. This took considerable attention. On my extreme right, I saw a cow (Black and white). I glanced over quickly.

I like cows.

I only looked for perhaps 500-750 milliseconds, then swung my gaze back to the road.

I like living even more than cows.

When my eyes hit the road, I immediately saw a smashed rodent of some kind on the right. Flattened roadkill. A squirrel, perhaps?

About 2 seconds later, a very clear image of a DEAD COW, legs sticking up in the air, flashed into my mind. I actually questioned whether or not I had seen that image not 2 seconds before. It took a bit of self-convincing. I kid you not.

What I am wondering, is, why? Was the smashed animal not a good enough exemplar of a live "noun" to attach the adjective "dead" to so it was transferred to the cow? (I use adjective and noun not in the literal linguistic sense.)

Or was it an effect of crossed m-channels in layer iv of V1?

Or maybe some kind of spreading activation hiccup?

What do you think? I'd actually like to come up with a nice experiment to see if I can recreate the effect.

Dan - That is truly bizarre. I have no idea why something like that would happen. It's possible that it's related to spreading activation and priming, as you noted.

Maybe if you showed pictures in rapid serial presentation, only one of which was an animal, and the last of which was just a bunch of blood, and then you asked subjects what was bloody in the last picture, they would probably say it was the animal (even though there was no animal in the bloody image).

There's also some interesting stuff on how emotion exacerbates the attentional blink effect. Could be related too, I guess...